Modes; Alarm Detection - Emerson 5301HxxxxxxxxxxxxxxZZ Series Reference Manual

Analog-Input Block
April 2019
Table J-2: BLOCK_ERR Conditions
ConditionNumber
12
13
14
15
J.6

Modes

The AI Function Block supports three modes of operation as defined by the MODE_BLK
parameter:
Manual (Man)
Automatic
(Auto)
Out of Service
(O/S)
J.7

Alarm detection

A block alarm will be generated whenever the BLOCK_ERR has an error bit set. The types of
block error for the AI block are defined above.
Process Alarm detection is based on the OUT value. You can configure the alarm limits of
the following standard alarms:
• High (HI_LIM)
• High high (HI_HI_LIM)
• Low (LO_LIM)
• Low low (LO_LO_LIM)
In order to avoid alarm chattering when the variable is oscillating around the alarm limit,
an alarm hysteresis in percent of the PV span can be set using the ALARM_HYS parameter.
The priority of each alarm is set in the following parameters:
• HI_PRI
• HI_HI_PRI
• LO_PRI
• LO_LO_PRI
Alarms are grouped into five levels of priority:
464
(continued)
Condition Name and Description
Readback Check Failed
Device Needs Maintenance Now
Power Up
Out of Service: The actual mode is out of service.
The block output (OUT) may be set manually.
OUT reflects the analog input measurement or the simulated value
when simulation is enabled.
The block is not processed. FIELD_VAL and PV are not updated and
the OUT status is set to Bad: Out of Service. The BLOCK_ERR
parameter shows Out of Service. In this mode, you can make
changes to all configurable parameters. The target mode of a block
may be restricted to one or more of the supported modes.
Reference Manual
00809-0100-4530
Rosemount 5300 Level Transmitter